Process for making bulbs for tank-valves.



A. T. HOPKINS.

PROCESS FOR MAKING BULBS FUR TANK VALVES.

.'APPLICAT|0N FILED MAYZI. 1914.

1,167,759. Patented Jan. 11,1916.-

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' ARTHUR T. HOPKINS, or CLEVELAND, onto, ASSIGNQR To'rHE MECHANICAL RUBBER COMPANY,- A CORPORATION or p NEW JERSEY.

Specification of Letters Patent.

Patented Jan. ii, ieic.

Original application filed 'April 13, 1914; Serial No. 8311308. Divided and this application filed May 21, 1914 Serial No. 839,935.

' To all whom it may} concern I which are adapted to close the end of the outlet pipe of a flush tank for water-closets and similar devices, .''which bulb is also of Qhio,

Be it"known that L-ARTHU'R T. HOPKINS, a. citizen of the: United States, residing at Cleveland, county of Cuyahoga, and State .have'invented. certainnew and useful Improvements in Processes for Making Bulbs for; Tanlcvalves, of which the following is a full, clear,- and exact disclosure.

My invention relates to that class of bulbs adapted to float on the surface of the Water Whenremoved from the outlet pipe.

The object of my invention is to produce'abulb or float which-is capable of being made entire y ofrubbenand which .at the same time will be especially effective in its operation by! reason of. the fact that its upper hemispherical portion will be practically' rigid and inflexible, While the lower hemispherical portion will be flexible and elastic and will readily conform'to the valve seat in theoutlct pipe. v

A .special object of my invention is to improve the process of manufacture of said same is vulcanized or cured to such degree bulbs so that the same may be made of white or .light colored rubber on its exterior. It

has been found in thefmanufact'ure'of articlesofwhite rubber composition when the as-toproduce considerable'stiifnessor rigidity, the high degree of heat required is liable toinjure and stain the whiteirubber and therefore make its appearance"objectionable. On the other hand, however, black or dark rubber composition may be cured, when it has'the requisite amount of sulfur or vulnation will not affect canizing substance incorporatedwith it, to a high degree, ther'eby producing the requisite stiifness without injuring'its strength or appearance. WVith this in: mind, I have devised abulb inwhich the upper hemispherical ortion contains afcoref of dark or black rub or which may be'vulcanlzed to.a greater degree than the lower hemispherical portion,

while at the same time the greater'vulcan-ithe 'lower portionof the bulb.

Fora] detailed description of one form'of the bulb and the process,

different steps inthe process of manufacture.

Referring to Fig. 1 of the drawing, the

numeral 1 indicates a supporting member for the hemispherical upper portion of the bulbas it is first formed of dark or black rubber capable of zation so as to make the same stiff and rigid.

This is preferably molded. from a"single homogeneous piece of raw rubber stock suba high degree of vulcanistantially cylindrical in form and sometimes called a sausage. ess of molding this portion 1 has inserted in its upper central point a thimble 2 into which the valve rod is adapted to be screwed. When this hemispherical portion 1 is molded it is then partially cured so as to give the same considerable rigidity and cause it to keep its shape, the curing being carried to such a point that the additional curing, given later on when the bulb is completely formed, will bring the total curing to the requisite point. The hemispherical supporting portion l which may for convenience be termed a core, having been formed and partially vulcanized as above described, is then coated on its inner and outer surfaces with a white rubber cement which will practically give a white color to both surfaces and at the same time form an adhesive. Thereafter a narrow ribbon or strip of comparatively. thin raw rubber stock is placed about the outer margin ofthe core 1 and the head 3, as indicated ate in Fig. 2,-thus forming a strong adhesive surface at the points where the two halves of the 'bulb are to be united. Next a sheet of raw thin white rubber stock is placed. over the upper outer surface of. thecore 1, as indicated at 5, so that it con-v to a line adjacent During the procsheet rubber stock is loo or flaps 'oaof substantially the same ,internal diameter as the flap (5. This formed lower portion 7 is then placed on the upper portion 1 and flaps 6 and S pressed firmly into contact so that the bulb assumes the form substantially as shown in Fig. 5. There is,

however, a small quantity of water or other into contact with the walls of the mold during the vulcanization or curing. The bulb is then removed from the mold and any surplus rubber buffed off, as indicated for instance at 10, so that the completed bulb assumes the form shown in Fig. '6, a small hole 10 being made at the lower end ofthe vertical axis of the bulb to permit the egress of the expanding fluidand the admission of air. In this completed bulb it will be observed that the same consists of a central hard core 1 in the upper portion which keeps the said portion firmly and permanently in shape, the thimble 2 being firmly embedded therein. The lowerportion of the bulb consists of a very flexible and elastic wall which is firmly united to the margin of the upper portion 1, while at the same time the whole is given an attractive appearance by reason of the fact'that it is completely covered with white or light vcolored rubber which also protects the hard rubber core from the effect of the water in which the bulb is immersed. This construction 'and process results in a bulb that is of much "greater effectiveness than the bulbs heretovalves, comprising, first forming a sup'portfore made, has greater durability'owing to the maintenance of shape and the reducedefi'ect of the water on the rubber, and has also a more attractive appearance than the ordinary bulb made of black or dark colored rubber ccmposition.

Having thus described this form of my invention, what I claim and desire to protect by Letters Patent is:

1. The process of making bulbs' for tank valves, comprising first forming'a supporting part of the vupper portion thereof, applying to the part so:formed by means of a suitable adhesive a covering of rubber stock, attaching to said part and said cover ing a hemispherical lower portion of rubbe'r stock capable of being vulcanized, and then vulcanizin'g the whole.

2.- The process of making bulbs for tank ing part of the upper portion thereof out of relatively hard material, applying to their!- ner and outer margins of the part so formed an. adhesive material, covering the surfaces thereof at said margins with rubber stock capable of being vulcanized, attaching to said coverings at said margins a hemispherical portion of said rubber stock, and then vulcanizing the whole.

3. The process of making bulbs for tank valves, comprising first forming a core for the upper portion thereof out of raw rubher stock capable of being vulcanized relatively hard, partly vulcanizing the same, applying to the part so formed an adhesive material, attaching to said upper portion a hemispherical portion of sheet rubber stock capable of being vulcanized relatively soft, and then vulcanizin the whole.

4. The process of making bulbs for tank valves, comprising, first forming a core for the upper portion thereof out of raw rubber stock capable of being vulcanized relatively hard, partly vulcanizing the same, applyin to the part so formed an adhesive materia covering the outer surface thereof with .a sheet of rubber stock capable of being vulcanized relatively soft, attaching to said up per portion a hemispherical portion of the last named rubber stock, and then-vulcanizing the whole.

5. The process of making bulbs for tank valves, comprising, first molding a core for the upper portion thereof out of raw-rub+ b er stock-capable of being vulcanized relat vely hard, partly vulcanizing-the same, applying a strip of rubber stock to the marg'ins thereof, attaching to said strip a hemispherical portion of raw sheet rubber stock capable of being vulcanized relatively soft,

and then vulcanizing the whole.

6. The process of making bulbs for tank valves, comprising, first molding a core for the upper portion thereof out of rubber stock capable of being vulcanized relatively hard, partly vulcanizing the same, covering the same with rubber cement, applying a strip of rubber stock to the margins thereof, covering the outer surface thereof with a sheet of rubber stock capable of being vulcanized relatively soft, attaching a hemi: spherical portion of the last named rubber stock in sheet form to said strip,and said surface covering, and then vulcanizing the whole.

7. The process of making bulbs for tank valves, comprising, first forming a core for the upper portion thereof out' of rubber stock capable of being vulcanized relatively vulcanized relatively soft and having an equatorial free flange, uniting said flanges,

trimming the same, and then vulcanizing the whole. r

8. The process of making bulbs for tank valves, comprising, first forming a supporting part of the upper portion thereof out of relatively hard material and having an internal marginal bead, applying to the outer margin thereof. and said beadan adhesive material, covering said margin and said bead-With rubber stock capable of being Vulcanized, attaching to said covering a hemispherical portion of the-last named rubber stock, and then vul'ca'nizing the whole.

9. The process-of making bulbs for tank valves, comprising, first forming a core for the upper portion thereof out of relatively hard material, applying to the inner and outer margins thereof an adhesive material, covering the said inner and outer margins with soft rubber stock capable of being vulcanized, attaching to said sheet stock a hemispherical portion of similar stock, and then vulcanizing the whole.

10. The process of making bulbs for tank valves, comprising, first forming a supporting part of the upper portion thereof out of relatively hard material, applying to the inner and outer margins thereof an adhesive material, covering the outer surface thereof and said margins with sheet rubber stock capable of being vulcanized, attaching to said marginal coverings a hemispherical portion of similar stock, and then vulcanizing the Whole.

Signed at Cleveland, county of Cuyahoga, State of Ohio, this 12th day of May, 1914;.

ARTHUR T. HOPKINS.

NVitnesses 4 RALPH 'H. TYRRELL, ELIZABETH M. Common. 

